whitespace, unused imports

docs/examples/ex20.py

@@ -3,7 +3,7 @@
 The stream-function :math:`\psi` for two-dimensional creeping flow is
 governed by the biharmonic equation
 
-.. math::  
+.. math::
     \nu \Delta^2\psi = \mathrm{rot}\,\boldsymbol{f}
 where :math:`\nu` is the kinematic viscosity (assumed constant),
 :math:`\boldsymbol{f}` the volumetric body-force, and :math:`\mathrm{rot}\,\boldsymbol{f} \equiv
@@ -48,6 +48,7 @@ def biharmonic(u, v, w):
 
     return ddot(dd(u), dd(v))
 
+
 stokes = asm(biharmonic, ib)
 rotf = asm(unit_load, ib)
 

docs/examples/ex24.py

@@ -11,7 +11,6 @@
 
 """
 
-from itertools import cycle, islice
 from pathlib import Path
 
 from matplotlib.pyplot import subplots
@@ -21,10 +20,9 @@
 from skfem import *
 from skfem.models.poisson import vector_laplace, laplace
 from skfem.models.general import divergence, rot
-from skfem.io import from_meshio
-import skfem.io.json
+from skfem.io.json import from_file
 
-mesh = skfem.io.json.from_file(Path(__file__).with_name("backward-facing_step.json"))
+mesh = from_file(Path(__file__).with_name("backward-facing_step.json"))
 
 element = {'u': ElementVectorH1(ElementTriP2()),
            'p': ElementTriP1()}

docs/examples/ex27.py

@@ -52,7 +52,6 @@
 import skfem.io.json
 
 from functools import partial
-from itertools import cycle, islice
 from pathlib import Path
 from typing import Tuple, Iterable